Process for obtaining coffee aromatics

ABSTRACT

By introducing steam into a bed of coffee to obtain steam distilled aromatics, the base extract obtained by extraction of the steamed coffee is more acid, and less desirable than extract obtained from unsteamed coffee. In the process of this invention, the steam is made to flow from the top of the bed of coffee, down through the bed. It was discovered that the extract obtained by extraction of coffee subjected to downflow steaming was less acidic and less degraded than extracts obtained from coffee treated with normal upflow of steam.

Unlted States Patent 1151 3,653,910 Pitchon [4 1 Apr. 4, 1972 [54]PROCESS FOR OBTAINING COFFEE 3,476,566 11/1969 White et al. ..99/65AROMATICS 3,421,901 1/1969 Mahlmann et a1. ..99/71 [72] Inventor: EsraPitchon, Flushing, NY. primary Examiner prank w Lune; [73] Assignee:General Foods Corporation, White Plains, Ass'smm Exammerwllham MenthkAttorney-Gera1d E. Jacobs, Bruno P.. Struzz1 and Thomas V.

Sullivan [22] Filed: Dec. 5, 1969 211 App]. No.2 882,708 [57] ABSTRACTBy introducing steam into a bed of coffee to obtain steam distilledaromatics, the base extract obtained by extraction of (g1 "99/155 theSteamed coffee is more acid, and less desirable than [58] Field 99/65 71tract obtained from unsteamed coffee. In the process of this invention,the steam is made to flow from the p of the bed of coffee, down throughthe bed. It was discovered that the ex- [56] References cued tractobtained by extraction of coffee subjected to downflow UNITED STATESPATENTS steaming was less acidic and less degraded than extractsobtained from coffee treated with normal upflow of steam. 2,432,75912/1947 Heyman ..99/71 3,244,531 4/1966 Clinton at a]. ..99/71 1 Claims,N0 Drawings PROCESS FOR OBTAINING COFFEE AROMATICS BACKGROUND OF THEINVENTION This invention concerns an improved method for obtainingcoffee aromatics via the technique of steaming roasted and groundcoffee. More particularly, it pertains to an improved steaming processwhich, after extraction of the steam coffee, yields an extract which isless degraded and more desirable than extracts obtained via prior artprocesses.

There are many different processes known to those skilled in the art forobtaining volatile aromatics from roasted and ground coffee via steamdistillation. Thus, in U.S. Pat. No. 3,421,901 a technique for steamingcoffee under atmospheric conditions to release aromatic vapors isdescribed and claimed. In column 2, lines 35 through 55, it will benoted that while operating parameters for critical variables arespecified, the standard technique of introducing steam at the lowerportion of a column of coffee is described. The standard technique ofintroducing steam into a bed of coffee in other prior art processes isto pass the steam up through the coffee, from the bottom of the bed tothe top of the bed. This upward flow of steam is used in processes thatcall for continuous draw-off of steam from the coffee at atmosphericconditions or under vacuum. Up-flow is also used in processes where thebed of coffee is isolated under pressure prior to drawing off the steamand aromatic vapors from the coffee.

It is a well known fact that extract obtained via extraction of steamedcoffee is undesirably acidic. In U.S. Pat. No. 3,420,674, prior artprocess for deacidifying extract are described and a new technique ofremoving deleterious acid components from steamed coffee prior toextraction is disclosed and claimed. Also, in co-pending applicationSer. No. 878,227 filed Nov. 19, 1969 entitled Process for RemovingDeleterious Acid Components from Steamed Coffee, a new technique forusing unsteamed coffee to deacidify extract obtained from steamed coffeeis disclosed and claimed.

It is readily apparent, that those skilled in the art recognize thatsteaming roasted and ground coffee results in the production ofundesirable acids which degrade the quality of coffee extract obtainedwhen extracting the steamed, roasted and ground coffees.

SUMMARY OF THE INVENTION It has now been discovered that by causing thesteam to flow in a downward direction through a bed of roasted andground coffee the production of undesirable acids is significantlyminimized. By utilizing downflow steaming in the prior art processes forobtaining aromatic volatiles from coffee, it is possible to then extractsoluble solids from the steamed coffee and obtain an extract which haslittle, if any, of the undesirable green-acid-sour flavor associatedwith extracts obtained when utilizing the prior art steaming processes.

It is most significant, that the simple technique of reversing thedirection of the flow of the steam, results in a marked improvement inthe quality of the extract obtained from steamed coffee. Surprisingly,the desirable effect of downflow steaming results in improved qualityextracts in essentially all of the known prior art processes for steamstripping aromatic volatiles from roasted and ground coffee.

DESCRIPTION OF THE PREFERRED EMBODIMENT The process of this invention isan improvement in prior art processes of removing aromatic volatilesfrom roasted and ground coffee by steam distillation. It is applicableto processes wherein a column is filled with a bed of coffee prior tosteaming. The improvement comprises passing steam through the coffee ina downward direction, rather than the normal upward flow of steam usedin the prior art processes.

The process of this invention is intended to yield aromatic volatileswhich are equivalent to those obtained when using a standard upflowsteaming technique. The advantage of this process is that the extractobtained when the steamed coffee is extracted does not have theundesirable green-acid-sour flavor normally associated with extractsobtained from steamed coffee.

It is believed that when steam is passed in an upward direction througha bed of coffee, condensate tends to form at the bottom of the bed. Thiscondensate then has to be boiled off by incoming steam in order to drivearomatic vapors to the outlet at the top of the bed. Thus, there is arefluxing action within the column when using an upward flow of steamand it is this refluxing which probably causes the formation ofundesirable acids. By using the process of this invention andintroducing the steam at the top of the column the refluxing isessentially eliminated and the production of undesirable acids isthereby minimized.

It may be possible, in practicing the process of this invention, toutilize lower steam pressures then are necessary in the prior artprocesses. However, the major significance of this invention is that thesimple technique of using downflow steaming results in a markedimprovement in the quality of extract obtained from the steamed coffeewhen utilizing well defined processes of the prior art.

In practicing the process of this invention, the roasted and groundcoffee is preferably loaded into a vessel wherein the height of the bedof coffee is at least two or three times the width of the bed. Thevessel used for steaming is preferably a percolator column which wouldthen be placed on stream in a standard extraction operation utilizing aset of percolators. By using the percolator column as the vessel inwhich the steaming operation is performed, additional material handlingof the steaming coffee prior to percolation is avoided and the overallprocess is therefore simpler.

The process of this invention will be further described and understoodby reference to the following examples:

EXAMPLE I A 5 inch diameter by 60 inch long percolator column was filledwith 8.0 Kg. of roasted and ground coffee. Steam at 20 p.s.i.g. wasintroduced into the bottom of the percolator with a top vent valve open.The gases and vapors leaving the top of the percolator were sent to acondenser using a coolant at 35 F. When 400 ml of condensate wascollected the steam valve at the bottom of the column and the vent valveat the top of the column were shut off thereby isolating the column. Thepercolator was then put on stream as the fresh stage of a standard 6column percolator set. Second stage extract was introduced into thebottom of this columnand 13.0 Kg. of extract was withdrawn in theconventional manner from the top of the column. The 400 ml of condensatewas added to the extract and the mixture was spray dried. underrelatively mild conditions (ie low inlet air temperature conditions).The resultant soluble coffee produces a beverage which had strong,brewed-coffee-like flavor. However, the beverage had an undesirablygreen-sour flavor.

EXAMPLE II The process of Example I was repeated with the followingmodification: Steam was introduced at the top of the column and thegases and vapors were drawn off at the bottom of the column. Theresultant soluble coffee produced a beverage with the same desirablebrewed coffee-like flavor attributed to the aromatic condensate added tothe extract. Advantageously, the green-sour notes found when usingupflow steaming (Example I) were not present in the product produced viathe improved process of this invention (downflow steaming).

EXAMPLE III A 5 inch diameter by 60 inch percolator was tilled with 8Kg. of roasted and ground coffee. Steam at p.s.i.g. was introduced intothe bottom of the percolator column with the top vent valve open. Whenthe temperature of the vapors leaving the top of the column reached 200F the top vent valve was shut off, thereby isolating the top of thecolumn, and pressure in the percolator was allowed to rise to 20p.s.i.g. which point the steam entering the column was shut off therebyisolating the bottom of the column. The percolator was held underpressure for two minutes and the top vent valve was then opened. Thepressure in the column caused aromatic vapors to flow from the column.These vapors were passed to a condenser using a coolant at 35 F.Approximately 200 ml of aromatic condensate was collected. Thepercolator column was then put on stream as the fresh stage in apercolator set of six columns and 13 Kg. of extract was withdrawn fromthe top of the column in a conventional manner. The 200 ml of aromaticcondensate was added to the extract and the mixture was spray driedunder gentle conditions. The resultant soluble coffee when prepared as abeverage resulted in a beverage with brewed coffee-like flavor but withflavor characteristics somewhat different than the product obtained inExample 1. However, again there was an undesirable green-sour flavornote.

EXAMPLE IV Example III was repeated, but the steam was introduced at thetop of the column and gases were vented out of the bottom of the column.After the column had been held under pressure, the aromatic vapors werewithdrawn from the bottom of the column. It was again found that thebeverage prepared from the soluble coffee of this process had thedesirable coffee-like flavor but the harsh green-sour notes observed inExample III were absent.

The foregoing examples were intended for illustrative purposes only andthe invention is intended to be limited by the appended claims.

What is claimed is:

1. An improved process for obtaining an aromatized soluble coffee fromroasted coffee comprising:

a. filling a fresh stage percolator column of a standard percolator setwith roasted and ground coffee wherein the height of the bed of coffeeis at least two times the width of the bed;

b. passing steam through the column of coffee, the steam flowing fromthe top of said column to the bottom of said column, whereby air in thecolumn is displaced with steam by allowing the air to flow out thebottom of the column as the steam is introduced;

. isolating the bottom of the column when the air has been displaced,building up a pressure in the column by continued addition of steam intosaid column, said steam contacting the coffee in the column and causingaromatic volatiles to be released from said coffee; and

isolating the top of the column;

e. maintaining the column under pressure for from 1 to 10 minutes, thetemperature of the coffee in the column being sufficiently high toprevent condensation of the steam;

f. opening the bottom of the column to permit water vapor and aromaticvolatiles to flow out the bottom of the column;

g. collecting the released aromatic volatiles by condensing the mixtureof water vapor and aromatic volatiles at a condenser temperature of lessthan F;

h. extracting the steamed coffee by introducing second stage extractinto the bottom of the fresh stage percolator column to obtain a coffeeextract;

i. adding the aromatic volatiles to the extract; and

j. drying the aromatized extract.

